The present invention relates to an electronic device having                a circuit board having a set of input contacts, a set of output contacts and an electrical circuit connected between the input contacts and the output contacts, and        a controller.        
The invention also relates to a method for testing a circuit board having a set of input contacts, a set of output contacts and an electrical circuit connected between the input contacts and the output contacts, including:
a) application of a predetermined test signal to the set of input contacts,
b) tapping off a response signal at the set of output contacts,
c) carrying out a signal analysis on the response signal.
Product piracy is growing continuously, including in the field of high-quality electronic devices. The circuit boards of such devices which are equipped with electronic components, in particular, are often easily copied and can be made in low-wage countries at non-competitively cheap prices. The manufacturers of the original devices and the original circuit boards suffer great losses as a result. Industrial property rights often have no effect in these situations, since most circuit boards have a design that is obvious to a person skilled in the art, in view of their special use.
Many original manufacturers counter this trend with an optical marking of their circuit boards that is supposedly difficult to copy, for example, with hologram stickers. Apart from the fundamental possibility of removing stickers, the holograms present a certain impediment to counterfeiters, but they can be copied with a sufficient effort or can at least be similarly mimicked to a high level of precision. In any case, protective measures of this type only affect those users who place value on the use of original parts. Users who specifically wish to use cheaper copies are not affected by such a copy-protection system.
In order to copy the electronic function of a circuit board, the visible component set thereof can be adopted. In order to reconstruct the internal wiring, it is known to apply a DC signal to the terminals of the circuit board in pairs and to test the connection of each terminal to all the other terminals and/or to test testing points on the circuit board by means of continuity measurements.
In a more complex method as disclosed in the basis reference JP 11026747 AA, a defined test signal is applied to a pair of input contacts and a resultant output signal is tapped off at a pair of output contacts. It is herein possible that an input contact is identical to an output contact and therefore a total of three test contacts can be used. It is also conceivable, however, that the set of input contacts and/or the set of output contacts includes more than two contacts. However, this variant, which is encompassed by the present invention, is not disclosed in the cited document. On suitable completion of the test and the logical analysis, electronic functions of a possibly component-equipped circuit board can be analyzed and then simulated in a hardware copy or numerically in software. Counterfeits of this type cannot be effectively counteracted through the known copying prevention methods.
In the field of card readers, i.e. devices which read or write information from and/or to IC cards which function as a storage medium and/or as an authorization confirmation, in order to recognize the card standard, it is known to establish and analyze a standardized identification communication between the reading device and active components of the card interface. The aim of the communication is to disclose the respective present interface standard as fully as possible to the reader, in order to enable the reader to select and use the protocols appropriate to the actual interface. Examples of such devices are disclosed in the references WO 01/06443 A1 and EP 1 607 899 B1.